The present invention relates to a heating apparatus and heating method for hardening an object to be heated located on an object to be bonded (bonding base object) or, for example, a bonding material for bonding an electronic component to the bonding base object, or more specifically for performing, for example, heating of a solder for solder-bonding, hardening of an electronic component fixing use thermosetting adhesive, or hardening of an encapsulation resin of an electronic component (IC chip, etc.), for example, in a process such as a process for mounting an electronic component onto a bonding base object (object to be bonded) such as a circuit board, a component, or a wafer via a bonding material, a process for bonding a board for interposer in a wafer state to a wafer via a bonding material such as a solder bump, or a process for forming a bonding material such as a bump for mounting a component in a state in which no component is mounted.
In recent years, a technique for mounting an electronic component on a circuit board requires multilayered circuit board, finer mounting density, dual-side mounting, and so on, while there is a growing demand for reducing the consumption power of the apparatus from the point of view of global environment.
Conventionally, in a reflow apparatus for soldering an electronic component onto a circuit board, there has been a heating apparatus that uses heating by a gas heated to a specified temperature, heating by radiant heat of infrared rays or the like, or a combination of them. However, the heating apparatus principally provides heat transfer by the gas heated to a specified temperature, and a variety of methods for circulating the heated gas are devised according to the conventional reflow method and reflow apparatus.
However, fabrication cannot be performed until reaching a specified temperature when a reduction in consumption power is considered. Therefore, it is required to achieve a reduction in consumption power in the operative stage of fabrication and achieve a reduction in consumption power in the inoperative stage of fabrication.
As a prior art example relevant to the method of circulating the heated gas, the method disclosed in Japanese Unexamined Patent Publication No. 6-61640 will be described with reference to FIG. 10, FIG. 11, FIG. 12, and FIG. 13.
The conventional reflow apparatus has a conveyance section 90b for conveying a circuit board 90a from an entrance to an exit, a preheating chamber 90f, a reflow heating chamber 90h, an air circulation path 90c in which air is circulated by a sirocco fan 90d, and an air heating device 90e provided for each air circulation path 90c. It is to be noted that the preheating chamber 90f and the reflow heating chamber 90h are collectively referred to as a furnace section.
The circuit board 90a receives thereon a printed solder paste, receives an electronic component mounted on the printed solder paste, and is conveyed through the reflow apparatus by the conveyance section 90b. In each air circulation path 90c, each sirocco fan 90d circulates a specified amount of air, and the air heating device 90e heats the specified amount of circulating air to a specified temperature. Through the above-mentioned processes, the circuit board 90a conveyed to the conveyance section 90b is heated by receiving on its upper surface the circulating air heated to the respective specified temperatures of the preheating chambers 90f and the reflow heating chambers 90h arranged from the entrance toward the exit. The board is preheated to a specified temperature in the preheating chambers 90f, then heated in a reflow manner to a specified temperature for reflow soldering in the reflow heating chambers 90h, and finally cooled by receiving cooling air in a cooling chamber 90g. 
However, in the aforementioned prior art construction, as shown in FIG. 12, a flow rate Q1 of the circulating air heated to the respective temperatures of the chambers is constant regardless of the operating state of the apparatus as to, for example, whether the temperature inside the apparatus is in a stable state (state in which a READY signal that is a loading enable signal is ON) at a specified temperature or in an adjusting state (state in which the READY signal that is the loading enable signal is OFF) as well as the presence or absence of a board inside the apparatus. This becomes a factor for increasing and consuming a time for the attainment of the stable state inside the furnace and consumption power.
FIG. 12 and FIG. 13 show timing charts of the operation of the apparatus to the attainment of the stable state inside the furnace. It is assumed that the heating chamber has the specified temperatures of a low setting temperature and a high setting temperature of t1 and t2, respectively, and t1 less than t2. If the atmospheric temperature inside the heating chamber is changed from the low temperature t1 to the high temperature t2 by changing the specified setting temperature of the heating chamber from the low temperature t1 to the high temperature t2 as shown in FIG. 12, then the furnace wall temperature of wall surfaces (heat insulator of, for example, calcium silicate) that constitute the heating chamber reaches the high temperature t2 later than the atmospheric temperature inside the heating chamber due to the influence of the thermal capacity and the rate of heat transfer. Conversely, if the atmospheric temperature inside the heating chamber is changed from the high temperature t2 to the low temperature t1 by changing the specified setting temperature of the heating chamber from the high temperature t2 to the low temperature t1 as shown in FIG. 13, then the furnace wall temperature of the wall surfaces that constitute the heating chamber also reaches the low temperature t1 later than the atmospheric temperature is inside the heating chamber due to the influence of the rate of heat transfer.
If a circuit board is heated immediately after the atmospheric temperature inside the heating chamber has reached the specified temperature, then there occurs a large difference in heating temperature by comparison with the stabilized stage since the furnace wall temperature is not stabilized, causing variations in quality. Therefore, by providing a time for stabilizing the furnace wall temperature (for example, after a lapse of a specified time (about 30 minutes to 45 minutes) by a timer after the atmospheric temperature has reached the specified temperature in FIG. 12 and FIG. 13) and forming an output of a loading enable signal of the circuit board into the apparatus (i.e., by turning on the READY signal that is the loading enable signal), the variations in quality of the circuit boards are restrained. However, according to this method, the time required for the furnace wall temperature to reach the specified temperature is long, and the time necessary from the temperature setting change to the enabling of heating is long, also causing an increase in consumption power during the time.
Furthermore, when the apparatus is in a heatable condition, the specified amount of heated air, which is required for maintaining the temperature of the atmosphere inside the furnace constant even when no circuit board exists inside the apparatus and controlling the variations in heating temperature of each circuit board when the circuit board is loaded, is circulated, and therefore, consumption power at the time when no circuit board is loaded in the apparatus is increased.
As shown in FIG. 33, a general conveyance section 90b is constructed of a fixed rail section 90i and a movable rail section 90j. The movable rail section 90j, which is supported in engagement by a screw 90k via a nut 90l by the rotation of a motor 90w and made slidable in a direction in which the movable rail section comes close to or away from the fixed rail section 90i, can cope with the width dimension (for example, 50 to 460 mm) of a variety of circuit boards 90a. Therefore, an opening 90m located between the chambers and at loading entrance and unloading exit of the apparatus has the maximum dimension (for example, 460 mm) or more of the circuit board 90a that can be conveyed.
However, in the aforementioned prior art example, the circulating air heated to the respective specified temperatures of the chambers will disadvantageously cause thermal interference through the opening located between the chambers and at the loading entrance and unloading exit of the apparatus. Therefore, each air heating device must supply a large quantity of heat, and this becomes a factor for increasing the consumption power. FIG. 34 shows the principle of the above-mentioned thermal interference. Assuming that heated air temperatures of adjoining two chambers 90n and 90o out of a preheating chamber, a heating chamber, and a cooling chamber are t1 and t2, respectively, and t1 less than t2, then air of the low temperature t1 flows into the chamber 90o. Particularly above the fixed rail section 90i and the movable rail section 90j, there is a consistent flow of air along the upper surfaces of the rail sections. Before the loading of a circuit board, a stable thermal equilibrium is provided after a lapse of a specified time. However, if a circuit board is loaded, then the air temperature is largely disordered and slowly restored into the stable state. Furthermore, if circuit boards are continuously loaded and the next circuit board is disadvantageously loaded before the restoration into the stable state, then the heating temperature is disadvantageously varied every circuit board, causing variations in quality.
As described above, an increase in consumption power is the issue with regard to any of the disadvantageous matters, and this has been demanded to be reduced.
Accordingly, the present invention has the object of providing a heating apparatus and heating method capable of reducing consumption power, giving solution to the aforementioned issues.
In order to achieve the aforementioned object, the present invention is constructed as follows.
According to a first aspect of the present invention, there is provided heating apparatus comprising:
a conveyance section for conveying a bonding base object to which an electronic component is bonded via an object to be heated;
a heating chamber for heating the object to be heated on the bonding base object by supplying at a specified flow rate heated gas heated to a specified temperature by a heating device as a heating source onto the bonding base object conveyed by the conveyance section; and
a gas supply heat quantity control unit for controlling the quantity of heat of the gas so that a supply heat quantity of the gas when no heat treatment for the object to be heated is needed is made smaller than a supply heat quantity of the gas when heat treatment for the object to be heated is needed.
According to a second aspect of the present invention, there is provided a heating apparatus as defined in the 1st aspect, wherein the gas supply heat quantity control unit makes the quantity of supply heat of the gas when no heat treatment for the object to be heated is needed smaller than the quantity of supply heat of the gas when heat treatment for the object to be heated is needed and controls the supply heat quantity of the gas so as to increase the supply heat quantity of the gas when setting changing of a temperature of the heating chamber to another specified temperature is executed further than the supply heat quantity of the gas when setting changing of the temperature of the heating chamber is not executed.
According to a third aspect of the present invention, there is provided a heating apparatus as defined in the 1st aspect, wherein the gas supply heat quantity control unit is a gas flow rate control unit, which makes the quantity of supply heat of the gas when no heat treatment for the object to be heated is needed smaller than the quantity of supply heat of the gas when heat treatment for the object to be heated is needed and controls the supply heat quantity of the gas so as to increase a supply flow rate of the gas when setting changing of a temperature of the heating chamber to another specified temperature is executed further than a supply flow rate of the gas when setting changing of the temperature of the heating chamber is not executed.
According to a fourth aspect of the present invention, there is provided a heating apparatus comprising:
a conveyance section for conveying a bonding base object to which an electronic component is bonded via an object to be heated;
a heating chamber for heating the object to be heated on the bonding base object by supplying at a specified flow rate heated gas heated to a specified temperature by a heating device as a heating source onto the bonding base object conveyed by the conveyance section; and
a gas flow rate control unit for controlling the gas supply flow rate so as to increase a supply flow rate of the gas when setting changing of a temperature of the heating chamber to another specified temperature is executed further than a supply flow rate of the gas when setting changing of the temperature of the heating chamber is not executed.
According to a fifth aspect of the present invention, there is provided a heating apparatus as defined in any one of the 1st through 4th aspects, wherein
further comprising a bonding base object detecting unit for detecting passing of the bonding base object through heating apparatus entrance and exit to detect presence or absence of the bonding base object inside the heating apparatus by the bonding base object detecting unit,
the gas supply heat quantity control unit executes control so as to determine that heat treatment for the object to be heated is needed upon detecting the presence of the bonding base object inside the heating apparatus to supply a quantity of supply heat for heat treatment use as a quantity of supply heat of the gas and determine that no heat treatment for the object to be heated is needed upon detecting the absence of the bonding base object inside the heating apparatus to supply a quantity of standby supply heat smaller than the quantity of supply heat for heat treatment use as the quantity of supply heat of the gas.
According to a sixth aspect of the present invention, there is provided A heating apparatus as defined in the 5th aspect, wherein the gas supply heat quantity control unit comprises a gas supply flow rate control section, which executes control so as to determine that heat treatment for the object to be heated is needed upon detecting the presence of the bonding base object inside the heating apparatus to supply a quantity of supply heat for heat treatment use as a quantity of supply heat of the gas and determine that no heat treatment for the object to be heated is needed upon detecting the absence of the bonding base object inside the heating apparatus to supply a quantity of standby supply heat smaller than the quantity of supply heat for heat treatment use as the quantity of supply heat of the gas.
According to a seventh aspect of the present invention, there is provided a heating apparatus as defined in the 5th aspect, wherein the gas supply heat quantity control unit comprises a gas temperature control section, which executes control so as to determine that heat treatment for the object to be heated is needed upon detecting the presence of the bonding base object inside the heating apparatus to heat the heated gas to a temperature for heat treatment use as a quantity of supply heat of the gas and determine that no heat treatment for the object to be heated is needed upon detecting the absence of the bonding base object inside the heating apparatus to lower the temperature of the heated gas to a standby temperature lower than the temperature for heat treatment use as the quantity of supply heat of the gas.
According to an eighth aspect of the present invention, there is provided a heating method comprising:
supplying at a specified flow rate heated gas heated to a specified temperature as a heating source onto a bonding base object, which is conveyed by a conveyance section and to which an electronic component is bonded via an object to be heated, inside a heating chamber so as to heat the object to be heated on the bonding base object, and
controlling a quantity of supply heat of the gas so that a supply heat quantity of the gas when no heat treatment for the object to be heated is needed is made smaller than a supply heat quantity of the gas when heat treatment for the object to be heated is needed.
According to a ninth aspect of the present invention, there is provided a heating method as defined in the 8th aspect, wherein, in executing the gas supply heat quantity control, the quantity of supply heat of the gas when no heat treatment for the object to be heated is needed is made smaller than the quantity of supply heat of the gas when heat treatment for the object to be heated is needed, and the quantity of supply heat of the gas is controlled so as to increase the supply heat quantity of the gas when setting changing of a temperature of the heating chamber to another specified temperature is executed further than the supply heat quantity of the gas when setting changing of the temperature of the heating chamber is not executed.
According to a tenth aspect of the present invention, there is provided a heating method as defined in the 8th aspect, wherein, in executing the gas supply heat quantity control, the quantity of supply heat of the gas when no heat treatment for the object to be heated is needed is made smaller than the quantity of supply heat of the gas when heat treatment for the object to be heated is needed, and the quantity of supply heat of the gas is controlled so as to increase the a supply flow rate of the gas when setting changing of a temperature of the heating chamber to another specified temperature is executed further than a supply flow rate of the gas when setting changing of the temperature of the heating chamber is not executed.
According to an 11th aspect of the present invention, there is provided a heating method comprising:
supplying at a specified flow rate heated gas heated to a specified temperature as a heating source onto a bonding base object, which is conveyed by a conveyance section and to which an electronic component is bonded via an object to be heated, inside a heating chamber so as to heat the object to be heated on the bonding base object, and
controlling a quantity of supply heat of the gas so as to increase a supply flow rate of the gas when setting changing of a temperature of the heating chamber to another specified temperature is executed further than a supply flow rate of the gas when setting changing of the temperature of the heating chamber is not executed.
According to a 12th aspect of the present invention, there is provided a heating method as defined in any one of the 8th through 11th aspects, wherein
whether or not the bonding base object has passed through an entrance and an exit of a heating apparatus including the heating chamber is detected, and
in controlling the gas supply heat quantity, the control is executed so as to determine that heat treatment for the object to be heated is needed upon detecting presence of the bonding base object within the heating method to supply a quantity of supply heat for heat treatment use as a quantity of supply heat of the gas and determine that no heat treatment for the object to be heated is needed upon detecting absence of the bonding base object within the heating method to supply a quantity of standby supply heat smaller than the quantity of supply heat for heat treatment use as the quantity of supply heat of the gas.
According to a 13th aspect of the present invention, there is provided a heating method as defined in the 12th aspect, comprising a gas supply flow rate control section, which executes control, when the gas supply heat quantity is executed, so as to determine that heat treatment for the object to be heated is needed upon detecting the presence of the bonding base object within the heating method to supply a quantity of supply heat for heat treatment use as a quantity of supply heat of the gas and determine that no heat treatment for the object to be heated is needed upon detecting the absence of the bonding base object within the heating method to supply a quantity of standby supply heat smaller than the quantity of supply heat for heat treatment use as the quantity of supply heat of the gas.
According to a 14th aspect of the present invention, there is provided A heating method as defined in the 12th aspect, comprising a gas temperature control section, which executes control, when the gas supply heat quantity control is executed, so as to determine that heat treatment for the object to be heated is needed upon detecting the presence of the bonding base object within the heating method to heat the heated gas to a temperature for heat treatment use as a quantity of supply heat of the gas and determine that no heat treatment for the object to be heated is needed upon detecting the absence of the bonding base object within the heating method to lower the temperature of the heated gas to a standby temperature lower than the temperature for heat treatment use as the quantity of supply heat of the gas.
According to a 15th aspect of the present invention, there is provided a heating apparatus as defined in any one of the 1st through 7th aspects, wherein
the conveyance section has a pair of rail sections to convey the bonding base object, and
at least either one of the pair of rail sections of the conveyance section is further provided with a heated gas flow path control member for changing to an inside of the heating chamber a flow path of the heated gas that tries to advance from the heating chamber toward an outside of the heating chamber at a boundary between the heating chamber and the outside of the heating chamber.
According to a 16th aspect of the present invention, there is provided a heating apparatus comprising:
a conveyance section, having a pair of rail sections, for conveying a bonding base object to which an electronic component is bonded via an object to be heated;
a heating chamber for heating the object to be heated on the bonding base object conveyed by the conveyance section by supplying heated gas heated to a specified temperature; and
a heated gas flow path control member for changing to an inside of the heating chamber a flow path of the heated gas that tries to advance from the heating chamber toward the outside of the heating chamber at a boundary between the heating chamber and an outside of the heating chamber, the heated gas flow path control member being located at least either one of the pair of rail sections of the conveyance section.
According to a 17th aspect of the present invention, there is provided a heating apparatus as defined in the 15th or 16th aspect, wherein the heated gas flow path control member is a shield plate, arranged just above at least either one of the pair of rail sections of the conveyance section and at the boundary between the heating chamber and the outside of the heating chamber, for blocking the flow path of the heated gas that tries to advance from the heating chamber toward the outside of the heating chamber.
According to an 18th aspect of the present invention, there is provided a heating apparatus as defined in the 15th or 16th aspect, wherein the heated gas flow path control member is a shield plate, which has a curved convex surface curved toward the outside of the heating chamber in a direction in which the bonding base object is conveyed and changes to the inside of the heating chamber the flow path of the heated gas that tries to advance from the heating chamber toward the outside of the heating chamber along the curved surface of the shield plate.
According to a 19th aspect of the present invention, there is provided a heating apparatus as defined in the 15th or 16th aspect, wherein at least either one rail section of the pair of rail sections of the conveyance section is fixed, the other rail section is a movable rail section arranged movably in a direction in which the movable rail section moves close to or apart from the fixed rail section according to a width dimension of the bonding base object, and
the heated gas flow path control member is connected to the movable rail section so as to be integrally moved and comprised of a shield plate for closing a region that belongs to the heating chamber and has no relation to board conveyance in an opening for conveying the bonding base object.
According to a 20th aspect of the present invention, there is provided a heating apparatus as defined in any one of the 15th through 19th aspects, wherein the heated gas flow path control member has a heat insulator for restraining heat conduction from the heated gas toward the outside of the heating chamber.
According to a 21st aspect of the present invention, there is provided a heating apparatus as defined is in any one of the 15th through 20th aspects, wherein
the heated gas flow path control member is comprised of at least either one rail section of the pair of rail sections of the conveyance section whose upper portion has a mountain-like cross-section shape, and makes the heated gas flow downward from above along the mountain-like cross section shape of the upper portion of the one rail section, blocking the heated gas from flowing toward the outside of the heating chamber along an upper surface of the rail section.
According to a 22nd aspect of the present invention, there is provided a heating apparatus as defined in any one of the 15th through 20th aspects, wherein
the heated gas flow path control member is comprised of at least either one rail section of the pair of rail sections of the conveyance section whose upper surface is sloped so as to be lowered toward an opposite side of the bonding base object conveyed by the rail sections of the conveyance section.
According to a 23rd aspect of the present invention, there is provided a heating apparatus as defined in the 15th or 16th aspect, wherein the heated gas flow path control member is constructed so as to change to the inside of the heating chamber the flow path of the heated gas that tries to advance from the heating chamber toward the outside of the heating chamber by a partition wall arranged at the boundary between the heating chamber and the outside of the heating chamber in at least either one of the pair of rail sections of the conveyance section.
According to a 24th aspect of the present invention, there is provided a heating apparatus as defined in any one of the 1st through 7th aspects and the 15th through 23rd aspects, wherein the object to be heated on the bonding base object is a bonding material for bonding the electronic component to the bonding base object.
According to a 25th aspect of the present invention, there is provided a heating apparatus as defined in any one of the 1st through 7th aspects and the 15th through 23rd aspects, wherein the object to be heated on the bonding base object is a solder or an electronic component fixing-thermosetting adhesive for bonding the electronic component to the bonding base object or an electronic component encapsulation resin for encapsulating the electronic component.
According to a 26th aspect of the present invention, there is provided a heating method as defined in any one of the 11th through 14th aspects, wherein the flow path of the heated gas that tries to advance from the heating chamber toward the outside of the heating chamber is controlled so as to change to the inside of the heating chamber at a boundary between the heating chamber for heating the object to be heated on the bonding base object conveyed by the conveyance section that has a pair of rail sections by supplying the heated gas heated to the specified temperature and the outside of the heating chamber in at least either one of the pair of rail sections of the conveyance section.
According to a 27th aspect of the present invention, there is provided a heating method for executing control so that a flow path of heated gas that tries to advance from a heating chamber toward an outside of the heating chamber is controlled so as to be changed to an inside of the heating chamber at a boundary between the heating chamber and the outside of the heating chamber for heating the object to be heated on the bonding base object which is conveyed by a conveyance section having a pair of rail sections and to which an electronic component is bonded via the object to be heated by supplying the heated gas heated to the specified temperature in at least either one of the pair of rail sections of the conveyance section.
According to a 28th aspect of the present invention, there is provided a heating method as defined in the 26th or 27th aspect, wherein the flow path of the heated gas that tries to advance from the heating chamber toward the outside of the heating chamber is blocked by a shield plate, which is arranged just above at least either one of the pair of rail sections of the conveyance section and at the boundary between the heating chamber and the outside of the heating chamber in controlling the heated gas flow path.
According to a 29th aspect of the present invention, there is provided a heating method as defined in the 26th or 27th aspect, wherein the flow path of the heated gas that tries to advance from the heating chamber toward the outside of the heating chamber is changed to the inside of the heating chamber by a shield plate, which has a curved convex surface curved toward the outside of the heating chamber in a direction in which the bonding base object is conveyed, along the curved surface of the shield plate in controlling the heated gas flow path.
According to a 30th aspect of the present invention, there is provided a heating method as defined in the 26th or 27th aspect, wherein at least either one rail section of the pair of rail sections of the conveyance section is fixed, the other rail section is a movable rail section arranged movably in a direction in which the movable rail section moves close to or apart from the fixed rail section according to a width dimension of the bonding base object, and
a region that belongs to the heating chamber and has no relation to board conveyance in an opening for conveying the bonding base object is closed by a shield plate connected to the movable rail section so as to be integrally moved in controlling the heated gas flow path.
According to a 31st aspect of the present invention, there is provided a heating method as defined in any one of the 28th through 30th aspects, wherein heat conduction from the heated gas toward the outside of the heating chamber is restrained by a heat insulator of the shield plate in changing to the inside of the heating chamber the flow path of the heated gas that tries to advance from the heating chamber toward the outside of the heating chamber in controlling the heated gas flow path.
According to a 32nd aspect of the present invention, there is provided a heating method as defined in any one of the 26th through 31st aspects, wherein the heated gas flows downward from above along the mountain-like cross-section shape of the upper portion of at least either one rail section of the pair of rail sections of the conveyance section in controlling the heated gas flow path, thus blocking the heated gas from flowing toward the outside of the heating chamber along the rail section upper surface.
According to a 33rd aspect of the present invention, there is provided a heating method as defined in any one of the 26th through 31st aspects, wherein at least either one rail section of the pair of rail sections of the conveyance section has an upper surface sloped so as to be lowered toward an opposite side of the bonding base object conveyed by the rail sections of the conveyance section, and the heated gas flows downward from above along the slope of the upper surface of the one rail section in controlling the heated gas flow path, thus blocking the heated gas from flowing toward the outside of the heating chamber along the upper surface of the one rail section.
According to a 34th aspect of the present the electronic component to the bonding base object or an electronic component encapsulation resin for encapsulating the electronic component.
According to a 37th aspect of the present invention, there is provided a heating apparatus as defined in any one of the 15th, 16th, and 18th through 25th aspects, wherein the heating chamber comprises a preparatory chamber for preliminarily heating the bonding base object before heat treatment and a heating use heating chamber to subject the bonding base object heated preliminarily to heat treatment, and the heated gas flow path control member is respectively provided at an entrance of the preparatory chamber and an exit of the heating use heating chamber.